package com.xu.chapter;

import java.util.Objects;

public class Test {

    public static void main(String[] args) {

        Integer a = null;
        Integer b = 1;
        if (Objects.isNull(a)){

        }else if (b==2){
            System.out.println("输出b");
        }else{
            System.out.println("else输出");
        }

    }
}
